Pneumatic tool



(No Model.)'

' J. S. MoGOY.

PNEUMATIC TOOL.

No. 323,053. Patented July 28, 1885.

WITNESSES INYENTOR AW W g% y- 7% ATTORNEYS.

N. PETERSv Phololiihugnphm Wnhinginn, D. C.

JAMES S. MCCOY, OF, BROOKLYN, NE\V YORK.-

PNEUMATIC TOOL.

LJPECIFICATION forming part of Letters Patent No. 323,053, dated July28, 1885.

Application filed September 1, 1884. (Yo modem To all whom it mayconcern:

Be it known that I, JAMES S. McCor, of Brooklyn, in the county of Kingsand State of New York, haveinvented anew and Improved Pneumatic Tool,which invention is fully set forth in the following specification.

This invention consists of a new and improved pneumatic tool for workingin stone and for other purposes, wherein a current of air or steamforced intothe tool causes a piston or striker to deliver rapid blowsupon a rod or bar to the outer end of which the cutting-point isattached, all as hereinafter fully described, and pointed out in theclaim.

Reference is to be had to the accompanying drawings, forming part ofthis specification, in which similar letters of reference indicatecorresponding parts in all the figures.

Figure l is a longitudinal sectional elevation of my new and improvedpneumatic tool. Fig. 2 is a front elevation of the piston-chamber, withthe outer shell removed to show the air-passages. Fig. 3 is a frontelevation of the opposite side of the piston-chamber, and Fig. 4 showsthe valve removed.

The section A of the main casing of the tool is formed with theair-inlet passage 0, eX- haust-passage a, and with the piston-chamber b,in which the piston or striker D tits. The lower section, B, of the maincasing is screwed to the section A, as shown, and is formed with thecountersink c, to receive the flat head or plate (Z of the tool-carryingrod or spindle O, placed in the section B. The part a of the section A,which incloses the pistonehambr b, is surrounded by the shell I), andthis part a has three slots or ports, 7t- Z m, and also the fourpassages or ports a a and 0 0, Fig. 1, made through it, and upon itsouter surface the said part a is faced off on opposite sides, as shownat p q, Figs. 2 and 3, and is grooved or recessed, as shown at r, s, t,and a.

The piston or striker D is made to fit exactly in the chamber 2), so asto control the passages and slots above mentioned made in the part a ofsection A, and is provided with the transversely-arranged valve 6, andis formed with the transverse air-passages h and t, which coincide withthe slots k Z, with the transverse passage j, (shown in dotted lines inFig. 1,) which coincides with the slot at, and with the verticalair-passages f g, (also shown in dotted lines in Fig. 1,) leading,respectively, to the top and bottom of the piston or striker from thechamber in which the valve 6 is placed.

The valvecis formed with the groovese' 6, arranged so that the valve inits reciprocating movement, causedby the pressure of air entering theports a and 0, alternately opens and closes all the air passages throughthe piston or striker D.

In operation air, being admitted through the induction -passage a intothe passage 1), (the striker being in the upper positi0n,) passesthrough passage 1. and port a, moving valve 6 to close passage t and toconnect passages m, j, and f, whereby air is admitted above the strikerD, and at the same time the passages h, k, and are connected to allowexhaust from below striker D through passages q and n. Then the airthrough passage a and port 0 moves valve 6 to close passage 71, toconnect passages 1a, and g, to admit air below the striker, and toconnect passages f, 13, and Z, to open the exhaust from above thestriker, and so on alternately, thus causingthe striker to have a rapidreciprocating movement, causing it to deliver rapid blows upon the plated of the tool-carrying rod 0, which forces the rod 0 suddenly down inthe tube B against the pressure of the spring-h, which, after each blowof the striker, returns the rod 0 to its original position.

The stroke of the piston or striker D upon the plate (1 acts to forcethe rod 0 down,partly by impact of the striker against the plate (Z andpartly by concussion of the air against said plate; hence theeffectiveness of the tool is increased by the increased surface obtainedby the plate (I, and by employing this plate (Z and the countersink cthe upward movement of the rod 0 and plate, caused by the reaction ofthe spring h, produces a partial vacuum below the plate cl, so thatthere is very little resistance of air to the downward movement of theplate (I.

' The tool thus constructed is adapted for drilling rock, dressing andcarving marble and other stone, calking boats, chasing brass cushion thepiston or striker and valve at IO and silver and other metal, and forvarious every point with air so perfectly as to secure other uses. theminimum amount of wear in the Working Having thus described myinvention, I claim parts of the tool. 5 as new and desire to secure byLetters Patent The combination of induction and eduction JAMES MCCOYports in the piston-chamber b, and striker D, Vitnesscs: controlled bythe valve 6 within the striker D, H. A. VVES'I, and the plate (1 of thetool-bearing rod to J O. SEDGWIOK.

